How Winlink 2000 Accommodates Loss of Internet

By Vic Poor, W5SMM, AAA9WL
February 13, 2008

There seems to be confusion has to how WL2K deals with the loss of Internet. Let me address this question and see if I can bring a little clarity to it.

As presently designed and deployed, the assumption is made that Internet may fail regionally but not globally. A disaster may take out the Internet infrastructure over an area of as much as several states or a single country but not the entire world.

If Internet fails in a given region those RMS sites that implement RMS Relay in the region will be able continue to exchange traffic locally on VHF and globally on HF. RMS Relay will provide the ability to reach WL2K stations on HF that are in areas where Internet is still functional and can still reach a CMS site. CMS sites are purposely geographically dispersed (Australia, Canada, U.S.) to provide the greatest possible redundancy.

Individual HF client stations using Paclink or AirMail will continue to be able to exchange traffic with out-of-region HF stations that can still reach any one of the CMS sites.

The whole idea is to keep users and the network entirely connected even when even large areas become isolated due to loss of Internet. The WL2K addressing would remain functional and anyone that can reach any functional HF or VHF port can exchange messages with anyone else anywhere in the system without thought about how it is routed.

It is argued by some that we should build a system to support total global failure of Internet. Army MARS has in fact plans to implement just such a system using HF accessible and interconnected CMS sites. I do not know the timetable for this implementation, but meanwhile the system outlined in the Winlink 2000 Roadmap document is currently being implemented, and will support any disaster scenario experienced to date.

An all-HF system, no matter how implemented, will have bandwidth and latency limitations that constrain its value. Served agencies need (and expect) a communications service will be able to handle a reasonable volume of complex traffic with good speed. To that end we need to provide a service that will make use of the best and fastest means available at any given time.

The WL2K mission is to provide, through a volunteer network, effective last resort communications in civil emergencies and personal communications in non-emergency conditions.